From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <michael@ellerman.id.au>
Date: Wed, 24 Jul 2013 11:16:40 +1000
From: Michael Ellerman <michael@ellerman.id.au>
To: Chen Gang <gang.chen@asianux.com>
Subject: Re: [PATCH v2] powerpc: kernel: remove useless code which related
 with 'max_cpus'
Message-ID: <20130724011640.GA6042@concordia>
References: <51ECCA10.7010709@asianux.com>
 <51ECCEA8.5040406@linux.vnet.ibm.com>
 <51ECD0BF.8080605@asianux.com> <51ECD3D4.9020405@asianux.com>
 <51ECD664.7040708@linux.vnet.ibm.com>
 <20130723134431.GF31944@concordia> <51EF1F97.3070409@asianux.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
In-Reply-To: <51EF1F97.3070409@asianux.com>
Cc: "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
 Thomas Gleixner <tglx@linutronix.de>, "paulus@samba.org" <paulus@samba.org>,
 chenhui.zhao@freescale.com,
 "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
List-Id: Linux on PowerPC Developers Mail List <linuxppc-dev.lists.ozlabs.org>
List-Unsubscribe: <https://lists.ozlabs.org/options/linuxppc-dev>,
 <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=unsubscribe>
List-Archive: <http://lists.ozlabs.org/pipermail/linuxppc-dev/>
List-Post: <mailto:linuxppc-dev@lists.ozlabs.org>
List-Help: <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=help>
List-Subscribe: <https://lists.ozlabs.org/listinfo/linuxppc-dev>,
 <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=subscribe>

On Wed, Jul 24, 2013 at 08:28:07AM +0800, Chen Gang wrote:
> On 07/23/2013 09:44 PM, Michael Ellerman wrote:
> > On Mon, Jul 22, 2013 at 12:21:16PM +0530, Srivatsa S. Bhat wrote:
> >> On 07/22/2013 12:10 PM, Chen Gang wrote:
> >>> Since not need 'max_cpus' after the related commit, the related code
> >>> are useless too, need be removed.
> >>>
> >>> The related commit:
> >>>
> >>>   c1aa687 powerpc: Clean up obsolete code relating to decrementer and timebase
> >>>
> >>> The related warning:
> >>>
> >>>   arch/powerpc/kernel/smp.c:323:43: warning: parameter ‘max_cpus’ set but not used [-Wunused-but-set-parameter]
> >>>
> >>> Signed-off-by: Chen Gang <gang.chen@asianux.com>
> >>
> >> This version looks good.
> > 
> > Agreed.
> > 
> > A good follow up patch, or actually series of patches, would be to
> > change the prototype of smp_ops->probe() to return void, and fix all the
> > implementations to no longer return anything.
> > 
> 
> Hmm... normally, a function need have a return value, it will make it
> more extensible (especially, it is an API which need be implemented in
> various sub modules).

A function doesn't need a return value, and if it needs one in future then
we'll add it then. We don't carry code around "just in case".

> Even though the return value may be useless, now, if the performance is
> not quite important in our case, I still suggest to have it (especially
> each various original implementation already has it).

It's dead code, it should be removed.

cheers